China launched the construction of a large astronomical observation project on the Qinghai-Xizang Plateau on Saturday, aiming to enhance the country's capabilities in exploring the cold, hidden universe by establishing a high-precision facility that addresses a notable gap in its existing astronomical infrastructure.

The new telescope, named the Xueshanmuchang 15-meter SubMillimeter Telescope (XSMT), will be located in the city of Delingha, northwest China's Qinghai Province, at an altitude of 4,800 meters. Led by the Nanjing-based Purple Mountain Observatory (PMO) under the Chinese Academy of Sciences, the project is scheduled to be completed in 2027.

Designed with a 15-meter aperture, the XSMT will support high-frequency submillimeter wave observations.

Submillimeter waves have wavelengths ranging from 0.1 to 1 millimeter, within which lie cosmic secrets invisible to visible light and near-infrared observations, such as the movement of interstellar dust, the distribution of molecular gases, and the birth and growth of stars.

While traditional optical telescopes cannot penetrate the dust of the universe, submillimeter wave facilities can not only reveal the laws of galaxy formation and evolution but also trace the origins of life-related molecules, playing a crucial role in studying the formation of stars and planets.

However, submillimeter wave observations have strict requirements for site conditions, one of which is that the atmospheric water vapor content above the site should remain low and stable.

According to scientists, the site of the telescope is located in the heart of the Qinghai-Xizang Plateau, known as "the roof of the world," featuring conditions such as high altitude, minimal human interference and extremely low water vapor, making it an ideal location for observations.

China lacks self-built and regularly operational observation facilities in the field of submillimeter wave astronomy. The planned XSMT will fill this gap and support China's frontier astronomical research, scientists said.

Li Jing, a PMO researcher, said the XSMT will focus on four scientific directions: extragalactic astronomy, Milky Way structure, time-domain astronomy and astrochemistry.

As China's first self-developed advanced submillimeter wave telescope, once completed, the XSMT is expected to join the next-generation Event Horizon Telescope – an Earth-sized virtual telescope network, contributing to the capture of dynamic images of black holes and enhancing China's international competitiveness in astronomy.